implementing-aws-nitro-enclave-security

Add a Condition block to the KMS key policy using kms:RecipientAttestation:ImageSha384 (PCR0) or kms:RecipientAttestation:PCR8. Decryption then only succeeds when the request includes a valid attestation document whose PCR values match the policy.

Create a Dockerfile with your application, build it with docker build, then run nitro-cli build-enclave with the Docker image URI and output file. The command produces an EIF and prints PCR0, PCR1, and PCR2 measurements used in KMS policies.

PCR0 is the image hash and changes on every rebuild, forcing a policy update per deployment. PCR8 is the signing certificate hash, so any image signed with the same certificate is trusted, making it better for production with rotating builds.

The allocator in /etc/nitro_enclaves/allocator.yaml likely reserves less memory_mib or cpu_count than run-enclave requests. Edit the file, restart nitro-enclaves-allocator.service, and confirm the service is active before launching.

Yes. Debug mode zeroes out PCR0, PCR1, and PCR2, so attestation-based KMS conditions can never match, and it exposes the enclave console. Verify nitro-cli describe-enclaves shows Flags as NONE in production.

Avoid them when the workload does not handle data requiring hardware-level isolation, when the instance type is not Nitro-based with at least 4 vCPUs, or when latency constraints make vsock communication overhead unacceptable.